TWI844121B - Aminolyzable benzoxazine resin cured product, manufacturing method and aminolysis method thereof - Google Patents

Abstract

An aminolyzable benzoxazine resin cured product, a manufacturing method and an aminolysis method thereof are provided in the present disclosure. The manufacturing method of the aminolyzable benzoxazine resin cured product includes a mixing step and a curing step. In the mixing step, a benzoxazine resin and a phenol are melted and evenly mixed to form a resin composition. In the curing step, the resin composition is heated to a curing temperature, so as to form the aminolyzable benzoxazine resin cured product. The curing temperature is 160°C to 230°C. By choosing the relatively lower temperature and adding the phenol to facilitate the curing process, the benzoxazine resin cured product with great material properties and chemical degradability can be manufactured. Therefore, the difficulty of recycling the benzoxazine resin cured product can be solved, and the goal of sustainable use thereof can be achieved.

Description

Amine-degradable benzoxazine resin solidified material and its preparation method and aminolysis method

The present invention relates to a benzoxazine resin solidified material, a preparation method thereof and an aminolysis method thereof, and in particular to an aminolyzable benzoxazine resin solidified material, a preparation method thereof and an aminolysis method thereof.

The amount of carbon dioxide emitted during the manufacturing of printed circuit boards (PCBs) and the treatment of their waste is greater than 100,000 kg CO ₂ /10,000 m ² PCB, which is the highest among current electronic product components. Therefore, how to effectively recycle waste PCBs to reduce carbon emissions has become a challenge faced by related industries. At present, the recycling method of waste PCBs is to crush the PCBs, take out the metal materials and recycle them. However, the plastic materials (including insulating resins and glass fiber cloth) in PCBs account for about 54.5%, and the resins in plastic materials are mostly stable thermosetting polymers, which makes the recycling rate of plastic materials less than 3%. This is the main reason for the difficulty of recycling and the high recycling cost. Therefore, the current main methods of disposing waste PCBs are still incineration and landfill.

Among the many resin materials, benzoxazine (BZ) resin can be selected as one of the manufacturing materials for PCB. Benzoxazine resin is formed by the reaction of phenols, formaldehyde and primary amine compounds. It has a special six-membered heterocyclic structure. The chemical structure of benzoxazine resin can be adjusted by changing the types of phenols and amines, so that benzoxazine resin has a huge molecular design space. In addition, the cured product of benzoxazine resin also has good mechanical properties, thermal properties, electrical properties and low surface energy. Therefore, benzoxazine resin is also widely used in PCB and electronic packaging materials.

In view of this, how to improve the degradation ability and recovery rate of benzoxazine resin solids remains a problem to be solved.

The purpose of the present invention is to provide a benzoxazine resin solidified product, which can be more easily degraded and recycled by adjusting the chemical structure of the benzoxazine resin.

One embodiment of the present invention provides a method for preparing an aminolyzable benzoxazine resin cured product, which comprises a mixing step and a curing step. In the mixing step, a benzoxazine resin and a phenolic compound are melted and uniformly mixed to obtain a resin composition, wherein the phenolic compound is used to promote the curing of the benzoxazine resin. In the curing step, the resin composition is heated to a curing temperature to form an aminolyzable benzoxazine resin cured product, wherein the curing temperature is 160°C to 230°C.

Accordingly, the method for preparing the aminolyzable benzoxazine resin cured product of the present invention uses a relatively low curing temperature for curing and simultaneously adds a phenolic compound to promote the curing reaction, so that the prepared benzoxazine resin cured product has good material properties and chemical degradability, thereby solving the problem of the difficulty in recycling the benzoxazine resin cured product and achieving the goal of sustainable utilization.

According to the aforementioned method for preparing the aminolyzable benzoxazine resin solidified material, the amount of the phenolic compound used can be greater than or equal to 20 phr. Furthermore, the amount of the phenolic compound used can be 20 phr to 25 phr.

According to the aforementioned method for preparing the aminolyzable benzoxazine resin curing material, the phenolic compound can be bisphenol A or phenolic resin.

According to the aforementioned method for preparing the aminated benzoxazine resin cured product, the curing temperature may be 180°C to 200°C.

According to the method for preparing the aminated benzoxazine resin cured product, the resin composition may further include an epoxy resin, and the equivalent ratio of the epoxy resin to the benzoxazine resin may not be greater than 1. Furthermore, the equivalent ratio of the epoxy resin to the benzoxazine resin may not be greater than 0.7.

Another embodiment of the present invention provides an aminated benzoxazine resin curing material, which is prepared by the above-mentioned method for preparing an aminated benzoxazine resin curing material, wherein the aminated benzoxazine resin curing material contains a phenoxy structure.

Another embodiment of the present invention provides a method for aminolysis of the aforementioned aminolyzable benzoxazine resin solidified material, comprising the following steps: performing a pre-decomposition mixing step and a heating step. In the pre-decomposition mixing step, the aminolyzable benzoxazine resin solidified material is mixed with an aliphatic amine compound to obtain an aminolyzed mixture. In the heating step, the aminolyzable benzoxazine resin solidified material is heated to decompose the aminolyzable benzoxazine resin solidified material in the aminolyzed mixture.

According to the aforementioned method, in the heating step, the aminolysis mixture is heated at an aminolysis temperature, and the aminolysis temperature may be 100° C. to 200° C. Furthermore, the aminolysis temperature may be 130° C. to 150° C.

According to the aforementioned method, the aliphatic amine compound can be triethylenetetramine.

According to the above method, the weight of the aliphatic amine compound can be more than twice the weight of the aminated benzoxazine resin curing material. Furthermore, the weight of the aliphatic amine compound can be 2 to 10 times the weight of the aminated benzoxazine resin curing material.

The following will discuss various embodiments of the present invention in more detail. However, this embodiment can be an application of various inventive concepts and can be specifically implemented in various different specific scopes. The specific implementation is for illustrative purposes only and is not limited to the scope of the disclosure.

In the present invention, the compound structure is sometimes represented by a skeleton formula, which may omit carbon atoms, hydrogen atoms, and carbon-hydrogen bonds. If the functional groups are clearly drawn in the structural formula, the drawn functional groups shall prevail.

Please refer to FIG. 1 , which is a flow chart of the steps of the method 100 for preparing an aminolyzable benzoxazine resin curing material of the present invention. One embodiment of the present invention provides a method 100 for preparing an aminolyzable benzoxazine resin curing material, which includes steps 110 and 120 .

Step 110 is a mixing step, in which a benzoxazine resin and a phenolic compound are melted and uniformly mixed to obtain a resin composition, wherein the phenolic compound is used to promote the curing of the benzoxazine resin.

Step 120 is a curing step, which is to heat the resin composition to a curing temperature to form an aminolyzable benzoxazine resin cured product, wherein the curing temperature is 160° C. to 230° C.

In detail, compared with traditional phenolic resins, the cross-linking behavior of benzoxazine resins during curing is affected by the curing temperature. When the curing temperature is low, the hexacyclic rings in the benzoxazine resins will form a phenoxy structure after ring-opening and cross-linking. The Mannich bridge structure in this phenoxy structure is similar to the Mannich bridge structure on the hexacyclic rings in the benzoxazine resins before curing. However, the carbon-oxygen bond of the Mannich bridge structure in the phenoxy structure is not stable and is easily rearranged at high temperatures, causing the lone pair of electrons on the oxygen atom to resonate to the adjacent position for cross-linking, and finally forming a relatively stable phenolic structure.

On the other hand, the carbon atoms on the Mannich bridge structure of the benzoxazine resin can undergo nucleophilic addition reaction with primary amine compounds. Therefore, the present invention utilizes the above characteristics, mixes the benzoxazine resin with a phenolic compound, and performs ring-opening polymerization at a relatively low curing temperature. The finally obtained aminated benzoxazine resin cured product has more phenoxy structures. Since the phenoxy structures are similar to the six-membered heterocyclic properties of the benzoxazine resin, the aminated benzoxazine resin cured product of the present invention can be degraded by amine compounds. Therefore, compared with the conventional benzoxazine resin cured product, the aminated benzoxazine resin cured product of the present invention has a greatly improved degradation ability.

The phenolic compound may be, for example, but not limited to, bisphenol A or phenolic resin, and the amount of the phenolic compound may be greater than or equal to 20 phr to promote the ring-opening reaction of the benzoxazine resin, which helps to increase the cross-linking degree of the benzoxazine resin and produce more phenoxy structures. Furthermore, the amount of the phenolic compound may be 20 phr to 25 phr to properly control the cross-linking degree of the benzoxazine resin. It is worth mentioning that the present invention can only use phenolic compounds to promote the cross-linking reaction of the benzoxazine resin, that is, no other promoters (such as aldehydes, amines, etc.) are added to ensure that the prepared aminolyzable benzoxazine resin cured product has a specific chemical structure and has excellent physicochemical properties and degradation ability.

The aforementioned curing temperature may be 180°C to 200°C. At this curing temperature, the curing reaction of the benzoxazine resin is more complete, which helps to improve the material properties of the benzoxazine resin cured product. The correlation between the curing temperature and the curing degree of the benzoxazine resin will be explained in detail in subsequent experiments and will not be elaborated here.

In addition, the resin composition may further include an epoxy resin, and the amount of epoxy resin added may be controlled by adjusting the equivalent ratio of the epoxy resin to the benzoxazine resin, and the equivalent ratio is calculated as: equivalent value of the epoxy resin/equivalent value of the benzoxazine resin. Specifically, in the method for preparing the aminolyzable benzoxazine resin cured product of the present invention, the epoxy resin may be added or not added when the benzoxazine resin and the phenolic compound are mixed. When the above-mentioned equivalent ratio is 0, it means that no epoxy resin is added to the aminated benzoxazine resin curing material; when the above-mentioned equivalent ratio is between 0 and 1, it means that epoxy resin is added to the aminated benzoxazine resin curing material; when the above-mentioned equivalent ratio is 1, it means that the equivalent ratio of epoxy resin to benzoxazine resin in the aminated benzoxazine resin curing material is 1:1.

The equivalent ratio of the epoxy resin to the benzoxazine resin may be no greater than 1. By adding the epoxy resin, the material properties of the benzoxazine resin cured product can be adjusted while reducing the manufacturing cost. Furthermore, the equivalent ratio of the epoxy resin to the benzoxazine resin may be no greater than 0.7, thereby controlling the proportion of the epoxy resin to retain the excellent degradation properties of the benzoxazine resin cured product.

Please refer to FIG. 2, which is a flow chart of the steps of the method 200 for aminolysis of an aminolyzable benzoxazine resin curing material of the present invention. Another embodiment of the present invention provides a method 200 for aminolysis of the aforementioned aminolyzable benzoxazine resin curing material, which comprises step 210 and step 220.

Step 210 is a pre-decomposition mixing step, which is to mix the aminated benzoxazine resin solidified material with an aliphatic amine compound to obtain an aminated mixture. The aliphatic amine compound can be triethylenetetramine (TETA), and the weight of the aliphatic amine compound can be more than twice the weight of the aminated benzoxazine resin solidified material to ensure a good degradation effect of the benzoxazine resin solidified material. Furthermore, the weight of the aliphatic amine compound can be 2 to 10 times the weight of the aminated benzoxazine resin solidified material, thereby avoiding excessive aliphatic amine compound residues that affect subsequent processing.

Step 220 is a heating step, which is to heat the mixture to be decomposed so that the decomposable benzoxazine resin solidified material in the mixture to be decomposed is decomposed. It is worth noting that the decomposable benzoxazine resin solidified material of the present invention has many phenoxy structures as decomposition points, and performs decomposition reaction as shown in the following chemical reaction formula: .

Specifically, in the heating step, the aminolysis mixture is heated at an aminolysis temperature, and the aminolysis temperature may be 100° C. to 200° C. to provide sufficient reaction energy. Furthermore, the aminolysis temperature may be 130° C. to 150° C. to further promote the aminolysis reaction.

The present invention is further illustrated by the following specific embodiments, which are used to facilitate those skilled in the art to which the present invention belongs, so that the present invention can be fully utilized and practiced without excessive interpretation. These embodiments should not be regarded as limiting the scope of the present invention, but are used to illustrate the materials and methods for implementing the present invention.

<Example 1>

2 g (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Man-Made Resin, product code PF3500), 0.86 g (0.0018 eq) of bisphenol A-type extended epoxy resin (Shangwei Xingye self-made epoxy KP-158, epoxy equivalent of 470 g/eq) and 20 phr of bisphenol A were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction, and finally a film of an aminolyzable benzoxazine resin cured product was obtained.

It is worth mentioning that the benzoxazine resin and the phenolic compound will start to crosslink at 150°C. Anyone skilled in the art can freely select an appropriate reaction time at the temperature disclosed in the present invention according to the content of the benzoxazine resin, the content of the phenolic compound and the selected equipment, so as to allow the benzoxazine resin and the phenolic compound to react completely to obtain the aminolyzable benzoxazine resin cured product of the present invention.

<Example 2>

2 g (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Man-Made Resin, product code PF3500), 0.86 g (0.0018 eq) of bisphenol A-type extended epoxy resin (Shangwei Xingye self-made epoxy KP-158) and 20 phr of phenolic resin (PN) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction, and finally a film of aminolyzable benzoxazine resin cured product was obtained.

<Example 3>

The amount of bisphenol A-type expanded epoxy resin in the resin composition of Example 2 was adjusted to 1.07 g (0.0023 eq), and the remaining ingredients and steps were the same as those of Example 2.

<Example 4>

The amount of bisphenol A-type expanded epoxy resin in the resin composition of Example 2 was adjusted to 1.23 g (0.0026 eq), and the remaining ingredients and steps were the same as those of Example 2.

<Example 5>

The final temperature of the gradual heating in Example 2 was adjusted to 200° C., and the remaining ingredients and steps were the same as those in Example 2.

<Example 6>

1.5 g (0.0069 eq) of diaminodiphenyl ether type benzoxazine resin (Changchun Synthetic Resin, product code PF3500), 0.42 g (0.0023 eq) of bisphenol A type epoxy resin (Changchun Synthetic Resin, product code BE188) and 20 phr of bisphenol A were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction, and finally a film of an aminolyzable benzoxazine resin cured product was obtained.

<Example 7>

The amount of diaminodiphenyl ether type benzoxazine resin in the resin composition of Example 6 was adjusted to 2 g (0.0092 eq) and the amount of bisphenol A type epoxy resin was adjusted to 0.84 g (0.0046 eq), and the remaining components and steps were the same as those of Example 6.

<Example 8>

The amount of diaminodiphenyl ether type benzoxazine resin in the resin composition of Example 6 was adjusted to 2 g (0.0092 eq) and the amount of bisphenol A type epoxy resin was adjusted to 1.13 g (0.0061 eq), and the remaining components and steps were the same as those of Example 6.

<Example 9>

The final temperature of the gradual heating in Example 6 was adjusted to 200° C., and the remaining ingredients and steps were the same as those in Example 6.

<Example 10>

1.5 g (0.0069 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, product code PF3500), 0.42 g (0.0023 eq) of bisphenol A epoxy resin (Changchun Synthetic Resin, product code BE188) and 20 phr of phenolic resin (PN) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction, and finally a film of an aminolyzable benzoxazine resin cured product was obtained.

<Example 11>

The amount of diaminodiphenyl ether type benzoxazine resin in the resin composition of Example 10 was adjusted to 2 g (0.0092 eq) and the amount of bisphenol A type epoxy resin was adjusted to 0.84 g (0.0046 eq), and the remaining components and steps were the same as those of Example 10.

<Example 12>

The amount of diaminodiphenyl ether type benzoxazine resin in the resin composition of Example 10 was adjusted to 2 g (0.0092 eq) and the amount of bisphenol A type epoxy resin was adjusted to 1.13 g (0.0061 eq), and the remaining components and steps were the same as those of Example 10.

<Example 13>

The final temperature of the gradual heating in Example 10 was adjusted to 200° C., and the remaining ingredients and steps were the same as those in Example 10.

<Example 14>

3 grams (0.0137 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, trade name PF3500) and 20 phr of bisphenol A were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction, and finally a film of an aminolyzable benzoxazine resin cured product was obtained.

<Example 15>

3 grams (0.0137 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, product code PF3500) and 20 phr of phenolic resin (PN) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C for a period of time, and then gradually heated to 200°C to complete the crosslinking reaction, and finally a film of an aminolyzable benzoxazine resin cured product was obtained.

＜Comparison Example 1＞

2 g (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, product code PF3500), 0.86 g (0.0018 eq) of bisphenol A-type extended epoxy resin (Shangwei Xingye self-made epoxy KP-158) and 2 phr of bisphenol A were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 120°C and maintained for a period of time, and then gradually heated to 150°C to complete the crosslinking reaction and form a film.

＜Comparison Example 2＞

The amount of bisphenol A in the resin composition of Comparative Example 1 was adjusted to 5 phr, and the remaining ingredients and steps were the same as those of Comparative Example 1.

＜Comparison Example 3＞

The amount of bisphenol A in the resin composition of Comparative Example 1 was adjusted to 10 phr, and the remaining ingredients and steps were the same as those of Comparative Example 1.

＜Comparison Example 4＞

The amount of bisphenol A in the resin composition of Comparative Example 1 was adjusted to 15 phr, and the remaining ingredients and steps were the same as those of Comparative Example 1.

＜Comparison Example 5＞

The amount of bisphenol A in the resin composition of Comparative Example 1 was adjusted to 20 phr, and the remaining ingredients and steps were the same as those of Comparative Example 1.

＜Comparison Example 6＞

2 g (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, product code PF3500), 0.86 g (0.0018 eq) of bisphenol A-type extended epoxy resin (Shangwei Xingye self-made epoxy KP-158) and 20 phr of phenolic resin (PN) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 120°C and maintained for a period of time, and then gradually heated to 150°C to complete the crosslinking reaction and form a film.

＜Comparison Example 7＞

1.5 g (0.0069 eq) of diaminodiphenyl ether benzoxazine resin (Chang Chun Resin, product code PF3500), 0.42 g (0.0023 eq) of bisphenol A epoxy resin (Chang Chun Resin, product code BE188) and 20 phr of bisphenol A were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 120°C and maintained for a period of time, and then gradually heated to 150°C to complete the crosslinking reaction and form a film.

＜Comparison Example 8＞

1.5 g (0.0069 eq) of diaminodiphenyl ether benzoxazine resin (Chang Chun Resin, product code PF3500), 0.42 g (0.0023 eq) of bisphenol A epoxy resin (Chang Chun Resin, product code BE188) and 20 phr of phenolic resin (PN) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 120°C for a period of time, and then gradually heated to 150°C to complete the crosslinking reaction and form a film.

＜Comparison Example 9＞

3 g (0.0137 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, product code: PF3500) was melted and coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, then gradually heated to 180°C to complete the crosslinking reaction and form a film.

＜Comparison Example 10＞

2 grams (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Changchun Synthetic Resin, product code PF3500) and 0.86 grams (0.0018 eq) of bisphenol A-type extended epoxy resin (Shangwei Xingye self-made epoxy KP-158) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction and form a film.

＜Comparison Example 11＞

1.5 g (0.0069 eq) of diaminodiphenyl ether benzoxazine resin (Chang Chun Resin, product code PF3500) and 0.42 g (0.0023 eq) of bisphenol A epoxy resin (Chang Chun Resin, product code BE188) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C for a period of time, and then gradually heated to 180°C to complete the crosslinking reaction and form a film.

＜Comparison Example 12＞

2 g (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Chang Chun Resin, product code PF3500), 1.13 g (0.0061 eq) of bisphenol A epoxy resin (Chang Chun Resin, product code BE188) and 20 phr of bisphenol A were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, and then gradually heated to 240°C to complete the crosslinking reaction and form a film.

＜Comparison Example 13＞

2 g (0.0092 eq) of diaminodiphenyl ether benzoxazine resin (Chang Chun Resin, product code PF3500), 1.13 g (0.0061 eq) of bisphenol A epoxy resin (Chang Chun Resin, product code BE188) and 20 phr of phenolic resin (PN) were melted and uniformly mixed to obtain a resin composition. Then, the resin composition was coated on a metal aluminum plate, placed in an oven and heated to 150°C and maintained for a period of time, and then gradually heated to 240°C to complete the crosslinking reaction and form a film.

＜Physical properties of aminated benzoxazine resin cured products＞

The following experimental results are obtained by measuring the glass transition temperature (T _g , °C) and the residual heat release (J/g) after curing of the above-mentioned embodiments and comparative examples using a differential scanning calorimeter (DSC). The heating rate during the measurement is 10°C/min, and the measurement results are listed in Table 1 below. Table 1. Glass transition temperature and residual heat release after curing Glass transition temperature (°C) Residual heat release (J/g) Glass transition temperature (°C) Residual heat release (J/g) Embodiment 1 119.22 21.55 Comparison Example 1 126.63 165.75 Embodiment 2 128.91 20.14 Comparison Example 2 N/A 169.16 Embodiment 3 131.91 31.90 Comparison Example 3 117.05 169.24 Embodiment 4 134.91 32.12 Comparison Example 4 N/A 169.86 Embodiment 5 141.84 12.89 Comparison Example 5 N/A 153.11 Embodiment 6 129.76 22.20 Comparative Example 6 N/A 134.60 Embodiment 7 135.72 32.87 Comparison Example 7 138.24 166.95 Embodiment 8 133.30 26.20 Comparative Example 8 153.60 146.45 Embodiment 9 135.76 5.50 Comparative Example 9 171.05 64.14 Embodiment 10 157.55 26.82 Comparative Example 10 136.60 37.60 Embodiment 11 161.10 27.54 Comparative Example 11 162.71 74.08 Embodiment 12 143.94 11.97 Comparative Example 12 161.35 9.44 Embodiment 13 170.44 4.22 Comparative Example 13 135.72 11.56 Embodiment 14 142.31 13.64 Embodiment 15 164.09 2.78

From the results in Table 1, it can be seen that in Examples 1 to 13 containing epoxy resin, the glass transition temperature of the prepared aminolyzable benzoxazine resin cured products can reach above 115°C, and compared with Comparative Examples 10 and 11 without adding phenolic compounds, the residual heat release after curing of Examples 1 to 13 with added phenolic compounds is greatly reduced (all less than 35 J/g); in addition, in Example 14, Example 15 and Comparative Example 9 which do not contain epoxy resin, it can be seen that the residual exothermic amount after curing of Example 14 and Example 15 which add phenolic compounds is much lower than that of Comparative Example 9 which does not add phenolic compounds, which proves that the addition of phenolic compounds can promote the ring opening of epoxy resin and benzoxazine resin at 180°C and 200°C, thereby increasing the degree of crosslinking.

Furthermore, the amount of phenolic compound added in Comparative Examples 5 to 8 is fixed, and the curing temperature is reduced to 150° C. From the results in Table 1, it can be seen that the residual heat release after curing of Comparative Examples 5 to 8 is higher than that of Examples 1, 2, 6 and 10 with curing temperatures of 180° C. and 200° C., which proves that the curing reaction can be more complete at curing temperatures of 180° C. and 200° C.

Furthermore, it can be seen from the measurement results of Comparative Examples 1 to 5 that when the dosage of the phenolic compound increases to 20 phr, the residual heat release after curing is significantly reduced, indicating that the reactivity of the curing reaction improves with the increase of the phenolic compound, and the dosage of the phenolic compound must reach a certain level to bring about a significant improvement effect.

If the amount of phenolic compounds is less than 20 phr, the ability of catalyzing the ring opening of benzoxazine resin and epoxy resin is relatively poor, which will reduce the overall cross-linking degree of the resin composition, resulting in excessive residual heat release. If used on PCB, it will affect its subsequent processing. If the amount of phenolic compounds is higher than 25 phr, because the molecules of phenolic compounds are relatively small, they will affect the arrangement of polymers after introduction, making the overall heat resistance of the cured product worse, resulting in a decrease in the glass transition temperature and degradation effect of the cured product.

＜Degradability of aminated benzoxazine resin cured products＞

The following experimental results are obtained by immersing the films prepared in the above-mentioned embodiments and comparative examples in triethylenetetramine, and then heating them in an oven at 135°C for 1.5 hours, and observing the changes in the films to evaluate their degradation ability. The observation results are listed in Table 2 below. Table 2. Degradation results Degradation results Degradation results Embodiment 1 Fully soluble Comparison Example 1 N/A Embodiment 2 Fragments Comparison Example 2 N/A Embodiment 3 No strength fragments Comparison Example 3 N/A Embodiment 4 No strength fragments Comparison Example 4 N/A Embodiment 5 Fragments Comparison Example 5 N/A Embodiment 6 Fragments Comparative Example 6 N/A Embodiment 7 Paste Comparison Example 7 N/A Embodiment 8 Paste Comparative Example 8 N/A Embodiment 9 Fragments Comparative Example 9 Fully soluble Embodiment 10 Fully soluble Comparative Example 10 Fully soluble Embodiment 11 Finely shredded rubber Comparative Example 11 Crumble, paste Embodiment 12 Finely shredded rubber Comparative Example 12 Strong large fragments Embodiment 13 Fine pieces Comparative Example 13 Strong large fragments Embodiment 14 Fully soluble Embodiment 15 Gel

It must be noted that since the residual heat release after curing of Comparative Examples 1 to 8 obtained in the previous experiment was too large, indicating that the curing reaction was incomplete, the degradation ability of Comparative Examples 1 to 8 is not discussed here.

From the results in Table 2, it can be seen that Examples 1 to 15 with curing temperatures of 180°C and 200°C can all be degraded by the method of the present invention, and Examples 1, 10 and 14 are all completely dissolved, while the remaining Examples form small pieces or lumps without strength after degradation. In contrast, although Comparative Examples 9 to 11 have degradation capabilities, they do not add phenolic compounds, resulting in a relatively large residual heat release after curing measured in the previous experiment (all greater than 35 J/g), indicating that the curing degree of Comparative Examples 9 to 11 is poor and has certain limitations in application. On the other hand, Comparative Examples 12 and 13 with a curing temperature of 240°C cannot be degraded into fragments without strength, indicating that their degradation effect is not good.

From the above experimental results, it can be seen that the degradation ability of the cured product is related to the crosslinking mechanism of the benzoxazine resin at different temperatures. The Mannich-type phenoxy structure formed by crosslinking at relatively low temperatures (curing temperature is 180°C and 200°C) is more susceptible to the lone pair electron attack of the primary amine compound than the Mannich-type phenol structure formed by crosslinking at high temperature (curing temperature is 240°C), thereby achieving the degradation effect.

In summary, the aminated benzoxazine resin cured product of the present invention is cured at a relatively low curing temperature and a phenolic compound is added to promote the curing reaction, so that the prepared benzoxazine resin cured product has good material properties and chemical degradability, thereby solving the problem of difficult recycling of benzoxazine resin cured products and achieving the goal of sustainable utilization.

The molding method of the aminolyzable benzoxazine resin cured product of the present invention is not limited to the method disclosed in the embodiments of the present invention, and it can be applied to extrusion molding, thermoforming, injection molding or other molding methods.

Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the attached patent application.

100: Method for preparing an aminated benzoxazine resin solidified material 200: Method for aminated benzoxazine resin solidified material 110,120,210,220: Steps

In order to make the above and other purposes, features, advantages and embodiments of the present invention more clearly understood, the attached drawings are described as follows: FIG. 1 is a step flow chart of the method for preparing the aminated benzoxazine resin solidified material of the present invention; and FIG. 2 is a step flow chart of the method for aminated benzoxazine resin solidified material of the present invention.

100: Method for preparing azolyzable benzoxazine resin solidified material 110,120: Steps

Claims (10)

A method for preparing an aminolyzable benzoxazine resin curing material comprises: performing a mixing step, wherein a diamino-derivative benzoxazine resin, an epoxy resin and a phenolic compound are melted and uniformly mixed to obtain a resin composition, wherein the phenolic compound is used to promote the curing of the diamino-derivative benzoxazine resin, the amount of the phenolic compound is 20phr to 25phr, the phenolic compound is bisphenol A or phenolic resin, and the equivalent ratio of the epoxy resin to the diamino-derivative benzoxazine resin is not greater than 1; and performing a curing step, wherein the resin composition is heated to a curing temperature to form an aminolyzable benzoxazine resin curing material, wherein the curing temperature is 160°C to 230°C. A method for preparing an aminolyzable benzoxazine resin curing material as described in claim 1, wherein the curing temperature is 180°C to 200°C. A method for preparing an aminolyzable benzoxazine resin curing material as described in claim 1, wherein the equivalent ratio of the epoxy resin to the diamine-derived benzoxazine resin is not greater than 0.7. A benzoxazine resin curing material that can be decomposed by aminolysis is prepared by the method for preparing a benzoxazine resin curing material that can be decomposed by aminolysis as described in any one of claim 1 to claim 3, wherein the benzoxazine resin curing material that can be decomposed by aminolysis contains a phenoxy structure. A method for performing aminolysis on the aminolyzable benzoxazine resin curing material as described in claim 4, comprising: performing a pre-decomposition mixing step, mixing the aminolyzable benzoxazine resin curing material with an aliphatic amine compound to obtain an aminolyzed mixture; and performing a heating step, heating the aminolyzable benzoxazine resin curing material to be aminolyzed, so that the aminolyzable benzoxazine resin curing material in the aminolyzed mixture is decomposed. As described in claim 5, in the heating step, the mixture to be aminolyzed is heated at an aminolyzed temperature, and the aminolyzed temperature is 100°C to 200°C. As described in claim 6, the aminolysis temperature is 130°C to 150°C. As described in claim 5, the aliphatic amine compound is triethylenetetramine. The method as described in claim 5, wherein the weight of the aliphatic amine compound is more than twice the weight of the aminolyzable benzoxazine resin curing material. The method as described in claim 9, wherein the weight of the aliphatic amine compound is 2 to 10 times the weight of the aminolyzable benzoxazine resin curing material.

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